mybatis比较轻量，适合开发比较小型的或者业务比较复杂的系统；
相对于hibernate来说可以灵活的写sql，更灵活的处理遇到的业务逻辑；
可以说hibernate是pojo实体对db的orm映射，而mybatis是pojo对sql的映射；
作为入门，先不考虑高级的特性，速度来一个CRUD再从源码和一个具体的业务来研究它的原理和高级特性；
CRUD基本思路：作为一种比较流行的持久层ORM框架，相当于三层架构中的dao层；
最终作为程序员的我们使用的SqlSession对象，先来个思路，再来个实现，最后研究细节；
环境准备，结合springmvc,做一个对博客文章的crud,下面贴出配置文件先；
第一列是依赖文件，都是在仓库中找到的最新的来用，兼容性如何暂且不管，先把简单的例子弄出来是关键；
第二列是web.xml的配置文件，定义一个spring的容器和mvc的url代理servlet；
第三列才是mybatis的使用环境准备，结合上图，上下往上推导定义出SqlSessionFactory,再定义出datasource和mapper配置文件；
第四列是springmvc的配置文件，相当常见，这里不解释；
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<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-webmvc</artifactId>
<version>4.0.1.RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-jdbc</artifactId>
<version>4.0.1.RELEASE</version>
</dependency>
<dependency>
<groupId>org.mybatis</groupId>
<artifactId>mybatis</artifactId>
<version>3.2.4</version>
</dependency>
<dependency>
<groupId>org.mybatis</groupId>
<artifactId>mybatis-spring</artifactId>
<version>1.2.2</version>
</dependency>
<!-- 数据源和jdbc驱动依赖 start-->
<dependency>
<groupId>commons-dbcp</groupId>
<artifactId>commons-dbcp</artifactId>
<version>1.4</version>
</dependency>
<dependency>
<groupId>commons-pool</groupId>
<artifactId>commons-pool</artifactId>
<version>1.6</version>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>5.1.29</version>
</dependency>
<dependency>
<groupId>com.google.guava</groupId>
<artifactId>guava</artifactId>
<version>15.0</version>
</dependency>
<!--log4j日志框架-->
<dependency>
<groupId>log4j</groupId>
<artifactId>log4j</artifactId>
<version>1.2.17</version>
</dependency>
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>jstl</artifactId>
<version>1.2</version>
</dependency>
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>jsp-api</artifactId>
<version>2.0</version>
<scope>provided</scope>
</dependency> |
|
<?xml version="1.0" encoding="UTF-8"?>
<web-app
xmlns="http://java.sun.com/xml/ns/javaee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/javaee
http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd"
version="3.0">
<display-name>mybatis</display-name>
<!--spring容器配置-->
<context-param>
<param-name>contextConfigLocation</param-name>
<param-value>classpath:config/context-config.xml</param-value>
</context-param>
<listener>
<listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
</listener>
<!--mvc配置-->
<servlet>
<servlet-name>mvc</servlet-name>
<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
<init-param>
<param-name>contextConfigLocation</param-name>
<param-value>classpath:config/dispatcher-config.xml</param-value>
</init-param>
<load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
<servlet-name>mvc</servlet-name>
<url-pattern>/</url-pattern>
</servlet-mapping>
</web-app> |
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<bean id="dataSource"
class="org.apache.commons.dbcp.BasicDataSource">
<property name="driverClassName"
value="${jdbc.mysql.driverClassName}"/>
<property name="url"
value="${jdbc.mysql.url}"/>
<property name="username" value="${jdbc.mysql.username}"/>
<property name="password"
value="${jdbc.mysql.password}"/>
<property name="maxActive"
value="${jdbc.mysql.maxActive}"/>
<property name="maxIdle"
value="${jdbc.mysql.maxIdle}"/>
<property name="initialSize" value="${jdbc.mysql.initialSize}"/>
<property name="maxWait"
value="${jdbc.mysql.maxWait}"/>
</bean>
<bean id="transactionManager"
class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
<property name="dataSource"
ref="dataSource" />
</bean>
<context:component-scan
base-package="com.sz.mybatis.framework.service">
<context:exclude-filter type="annotation"
expression="org.springframework.stereotype.Controller"/>
</context:component-scan>
<context:annotation-config />
<tx:annotation-driven />
<bean id="sqlSessionFactory"
class="org.mybatis.spring.SqlSessionFactoryBean" scope="singleton" >
<property name="dataSource"
ref="dataSource" />
<property name="typeAliasesPackage"
value="com.sz.mybatis.framework.domain.blog" />
<property name="mapperLocations">
<list>
<value>classpath:com/sz/mybatis/framework/persist/BlogMapper.xml</value>
</list>
</property>
</bean>
<bean id="sqlSession"
factory-bean="sqlSessionFactory"
factory-method="openSession" scope="prototype"></bean>
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<context:component-scan
base-package="com.sz.mybatis.admin.controller">
<!--<context:include-filter
type="annotation"
expression="org.springframework.stereotype.Controller"/>-->
</context:component-scan>
<mvc:default-servlet-handler/>
<mvc:annotation-driven/>
<bean
class="org.springframework.web.servlet.view.InternalResourceViewResolver">
<property name="suffix"
value=".jsp"></property>
<property name="prefix" value="/page/"></property>
<property name="viewClass"
value="org.springframework.web.servlet.view.JstlView"/>
<!--<property name="contentType"
value="UTF-8"/>-->
</bean>
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来一个博客对象的增删改查先；controller先来，这是概要；
然后是url映射：
servic直接略过，主要关注dao的实现，先来个接口先；
实现：
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package com.sz.mybatis.framework.service.impl;
import com.google.common.collect.ImmutableList;
import
com.sun.deploy.association.utility.AppConstants;
import
com.sz.mybatis.framework.domain.Msg;
import
com.sz.mybatis.framework.domain.PageConfig;
import
com.sz.mybatis.framework.domain.blog.Blog;
import
com.sz.mybatis.framework.persist.BlogDao;
import
com.sz.mybatis.framework.persist.BlogMapper;
import
com.sz.mybatis.framework.service.BlogService;
import
com.sz.mybatis.framework.util.SystemConstant;
import
org.apache.ibatis.session.SqlSession;
import
org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import java.util.List;
/**
* Created with IntelliJ IDEA.
*
User: cutter.li
* Date: 14-2-28
* Time:
下午3:07
* 服务实现类
*/
@Service
public class BlogServiceBean implements BlogService {
@Autowired
SqlSession session;
private BlogMapper getBlogMapper() {
return
session.getMapper(BlogMapper.class);
}
@Override
public
Msg list(PageConfig pageConfig) {
if (pageConfig != null) {
BlogMapper blogMapper = getBlogMapper();
List<Blog> blogList= blogMapper.list(pageConfig);
Msg
msg=new Msg();
if(blogList!=null)
{
msg.setCode(SystemConstant.SUCCESS);
msg.setMessage(SystemConstant.SUCCES_MESSAGE);
msg.setData(blogList);
}
return msg;
}
return null;
}
@Override
public
Blog listSingle(int id) {
if (id > 0) {
BlogMapper blogMapper = getBlogMapper();
Blog blog = blogMapper.selectBlog(id);
return blog;
}
return null;
}
@Override
public
void modify(Blog blog) {
getBlogMapper().updateBlog(blog);
}
@Override
public
void insert(Blog blog) {
getBlogMapper().insertBlog(blog);
}
@Override
public
void remove(int id) {
getBlogMapper().deleteBlog(id);
}
} |
配置文件:
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper
PUBLIC "-//mybatis.org//DTD
Mapper 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper
namespace="com.sz.mybatis.framework.persist.BlogMapper">
<select id="selectBlog" resultType="Blog">
select * from Blog where id = #{id}
</select>
<select id="list"
parameterType="com.sz.mybatis.framework.domain.PageConfig"
resultType="com.sz.mybatis.framework.domain.blog.Blog">
select * from Blog
order by #{sortField} #{sortOrder} limit #{start},#{pageSize}
</select>
<insert id="insertBlog"
parameterType="Blog">
insert into Blog
(title,contentSummary,contentDetail)
values(#{title},#{contentSummary},#{contentDetail})
</insert>
<update id="updateBlog" parameterType="Blog">
update Blog set
title=#{title} , contentSummary=#{contentSummary}
,contentDetail=#{contentDetail} where id=#{id}
</update>
<delete id="deleteBlog" parameterType="int">
delete from Blog
where id=#{id}
</delete>
</mapper> |
一个接口方法对应一条配置，通过id对应起来，据说可以在类的注解上面写sql，那会更简单，有空我改成注解的，敬请期待…
来几张效果图先：
两个图对比标识完成了分页的操作；
两个图对比表示实现了增加的功能；
两个图对比表示实现了编辑的功能；
最后标识实现了删除的功能；
到这里crud的程序算完成了，mybatis成功的入门了…
对了，附上源码...
mybatis笔记1 基本的配置和操作,布布扣,bubuko.com
mybatis笔记1 基本的配置和操作
原文：http://www.cnblogs.com/snidget/p/3578341.html
